Apparatus for and method of lining conduits

ABSTRACT

Apparatus ( 10 ) for lining an internal surface of a pipeline ( 15 ) or other conduit. The apparatus ( 10 ) comprises an installation head ( 21 ) which is progressively moved along the pipeline ( 15 ) for installing a flexible liner ( 11 ) onto the interior surface ( 13 ) of the pipeline ( 15 ). The flexible liner ( 11 ) comprises a tube structure ( 17 ) undergoing eversion within the pipeline ( 15 ). The tube structure ( 17 ) comprises a resin absorbent material. The installation head ( 21 ) has a contact surface ( 23 ) against which the tube structure ( 17 ) acts during eversion thereof, the contact surface ( 23 ) having means for delivery of a curable resin to the everting portion of the tube. The installation head ( 21 ) advances along the pipeline ( 15 ) under the influence of a driving force comprising (at least in part) pressure applied to the installation head ( 21 ) through the everting tube structure ( 17 ).

FIELD OF THE INVENTION

This invention relates to an apparatus for, and a method of, liningducts and other conduits. The invention also relates to a tube structurefor use in the apparatus and method.

The invention has been devised particularly, although not solely, forinternally lining fluid flow conduits and is applicable to both gravityflow pipelines, such as pipelines for sewer and stormwater drainage, andpressurized pipelines such as water and gas pipelines.

The invention may be used for the renovation of existing pipelines andother conduits in various states of deterioration, with problems rangingfrom impaired hydraulic performance to partial or complete loss ofstructural integrity resulting in a total failure to contain the fluidswithin, or stop the ingression of fluids from without, the pipe.Additionally, the invention may be used to line existing pipelines andother conduits in order to extend the service life thereof. Similarly,the invention may be used to line new pipelines and other conduits inorder to provide longevity in terms of service life.

The lining may comprise a continuous layer, or alternatively one or morelocalised layers, applied within the duct or other conduit.

BACKGROUND ART

Throughout the world, there are numerous pipelines which are approachingor have exceeded their service life, which have been installed inextreme environments or which were incorrectly installed. Consequently,the pipelines have deteriorated to an extent that remedial action isrequired in order to maintain their effectiveness or to avoid leakage.This is particularly so for municipal infrastructure involving pipenetworks such as sewers and water mains using materials such asvitrified clay (VC) and reinforced concrete (RC). Typical structuralproblems with such pipe networks include cracking or poor jointingleading to water ingress, sewage egress, root intrusion or calcificationbuild-up on the pipe walls. The structural problems can also includelongitudinal cracking and circumferential cracking of pipes within thenetwork, leading to ovality or partial collapse of the pipes.

Systems used for the renovation of such conduits generally fall withinthree broad categories. The first category involves traditional methodsincluding manually applied liners and cover shotcrete, grouting andplaced thermoplastic liners. The second category includes placedthermoplastic liners installed automatically, using materials such asuPVC and HDPE and cover mechanically or thermally expanding thethermoplastic liner against the conduit wall. The third categoryinvolves the placement of generally thermoset or catalysed or UVradiation energy cured liners which are typically placed through theeversion of an already resin-impregnated “sock” generally of fibreglassmaterials. A newer system employs a resin coating on the surface of aflexible tube of aligned polypropylene fibres. The resin on the surfaceis, upon eversion, forced into the sides of the pipe, the objectivebeing the creation of a bonded liner to the pipe. This does not, inpractice, provide a successful consistent bonded liner, as therequirements for the resin layer or thickness varies dependent upon theholes and cracks in the pipe as well as other requirements for the useof the resin in the pipe.

One proposal to line existing pipelines is disclosed in US Pat.4,687,677 (Jonasson). The proposal involves introduction of a flexiblehose-shaped liner containing a curable plastic material into thepipeline to be lined. The flexible liner is introduced into the pipelinein an uncured state and is pressed out against the inside of thepipeline by means of compressed air. The flexible liner is then hardenedin place by exposing the curable thermoset resin material to radiationenergy. A somewhat similar proposal is disclosed in WO 92/16784(Lundmark). In this latter proposal, the hose-shaped liner is introducedinto the pipeline by either drawing in the liner or by everting theliner into the pipeline.

A disadvantage of such proposals involving installation of a liner whichcontains a curable resin material and which can be cured upon exposureto radiation energy or heat is that the liner must be manufactured,prepared and stored under fully-controlled conditions at a productionfacility remote from the installation site and then transported to theinstallation site. In addition to the transport storage and handlingcosts involved with storing the liners, there is also the wastage causedby premature curing of the liners in storage. Further, if prematurecuring is not detected prior to installation, there is the cost ofremoving the failed liner and commencing the installation again with anew liner. This can contribute significantly to the cost of a pipelining operation.

There have been various proposals for lining conduits involvinginstallation of a liner as a tube which is everted into the passagewaybeing lined, and which comprises an inner layer of resin absorbentmaterial surrounded by a membrane. As the tube is everted, uncured resinis applied to the everting face of the tube to impregnate the layer ofresin absorbent material which is then presented to the surface of thepassageway. The everted tube is held in place by fluid pressure untilthe resin cures to form a rigid lining on the passageway surface. Onesuch proposal is described in GB 1512035.

With lining proposals involving eversion of a tube comprising a layer ofresin absorbent material, it is most important for there to be effectiveimpregnation of the resin absorbent material. EP 0 082 212 attempts toaddress this need by provision of a vacuum inside the tube in order toremove air from the resin absorbent material at the everting face sothat such material is in an optimum condition to receive the resinpresented to it, thereby ensuring effective penetration of the resininto the absorbent material. However, the method outlined of providingthe application of vacuum to the tube is a cumbersome procedure,involving positioning of a vacuum pipe within the tube when it is in acollapsed condition prior to eversion.

Additionally, the resin is presented to the everting face of the tube inthe form of a large plug of uncured resin in the passageway to whichback pressure is applied. This is employed to support the plug of resinand drive the plug, and the seal within the pipe, forward. Consequently,it is necessary for the everting tube to push the plug of uncured resinalong the passageway, with the result that the plug of uncured resin canbe under high and variable pressure. The fact that the plug of resin isunder high variable and uncontrolled pressure can cause difficulties,one being that ongoing delivery of replenishment resin to the plug canbe complicated. Further, as there is no monitoring present, there is noknowledge of the size or consistency of the volume of resin. Inparticular, there is no feed back to determine if the volume trappedbetween the everting tube and the seal is air or resin. Also, with anuncontrolled resin “plug”, the air that becomes trapped in the resinvolume cannot escape.

It is against this background, and the problems and difficultiesassociated therewith, that the present invention has been developed.

The reference to prior art in this specification is not, and should notbe taken as, an acknowledgement or any form of suggestion that thatprior art forms part of the common general knowledge in Australia.

DISCLOSURE OF THE INVENTION

According to first aspect of the present invention there is providedapparatus for lining an internal surface of a conduit, comprising a bodyadapted to be progressively moved along the conduit for installing aflexible tube onto the internal surface, the flexible tube undergoingeversion within the conduit, the body presenting a contact surfaceagainst which the tube acts during eversion thereof.

The internal surface may comprise an interior wall surface of theconduit or a substrate applied thereto.

The flexible tube structure may be of any appropriate form. In onearrangement, it may for example be of unitary construction comprising atubular element. In another arrangement, it may for example be ofcomposite construction comprising several layers.

The body may be caused to move along the conduit in any appropriate way,such as for example by application of a driving force thereto. Thedriving force may involve a towing force applied by way of a towline orpressure applied to the body through the everting tube (arising from thepresence of a inflation fluid within the tube), or a combinationthereof. Where the body is caused to move by pressure applied throughthe everting tube, it may be necessary to provide a retarding force tocontrol the rate of advancement of the body. The retarding force may beapplied in any appropriate way, such as by a brake sled operablyconnected to the body and in friction engagement with the interiorsurface of the conduit.

Preferably, the contact surface has means for delivery of an agent tothe everting portion of the tube.

The means for delivery of the agent may include a plurality of ports inthe contact surface, the ports communicating with a supply of the agent.

The contact surface may be defined by a plate having apertures thereinincorporating the ports.

The plate may be rigidly or elastically supported.

The agent may comprise a curable resin. The curable resin, when appliedto a resin absorbent material and allowed to harden, can together withsuch material provide a composite material forming a rigid structureproviding a liner for lining the internal surface.

The conduit may be lined continuously along the length thereof or atleast along the length of a longitudinal section thereof, oralternatively at one or more localised areas within the conduit.

Where the internal surface of the conduit is lined continuously for thefull length thereof or along at least a longitudinal section of thelength thereof, the tube may comprise resin absorbent material. Theresin absorbent material may provide the entirety of the tube structureor a portion thereof. Where the resin absorbent material provides aportion of the tube structure, it may be provided as a layer and thetube structure may comprise a further layer, typically in the form of amembrane having characteristics selected according to characteristicsrequired for the lining.

Where the lining is discontinuous in that it is applied to one or morelocalised areas within the pipeline, the tube structure may comprise amembrane on which are carried one or more liner portions comprisingresin absorbent material, the arrangement being that the tube structureupon eversion presents the liner portions to the internal surface of theconduit to provide the localised lining therefor. Typically, the tubestructure is subsequently withdrawn, leaving the liner portions inposition to provide the localised lining.

Where the tube structure comprises resin absorbent material, suchmaterial may be dry or pre-impregnated with resin. In the latter case,it may be either partially or fully impregnated with resin.

According to second aspect of the present invention there is providedapparatus for lining an internal surface of a conduit comprising a bodyadapted to be progressively moved along the conduit for installing aflexible liner onto the internal surface, the flexible liner comprisinga tube structure undergoing eversion within the conduit, the tubestructure comprising resin absorbent material, which may bepre-impregnated with resin or not the body presenting a contact surfaceagainst which the tube structure acts during eversion thereof, thecontact surface having means for delivery of a curable resin to theeverting portion of the tube structure.

Where the contact face is defined by a plate, one face thereof maydefine the contact surface and an opposed face thereof may provide aboundary for a resin chamber from which resin may be delivered to thecontact face by way of the apertures therein. This also assists in therapid and controllable release of any air trapped within the liner. Asthe air is purged from the highest point within the chamber all thechamber is filled with resin.

With this arrangement, the pressure exerted by the everting tubestructure is exerted primarily on the contact surface and not onto theresin itself, and in particular not on the resin contained within theresin chamber. Consequently, the resin can freely flow into contact withthe everting tube structure and can be easily replenished by delivery ofreplenishment resin to the resin chamber. In this embodiment the resinpressure remains generally constant and can thus be controlled through acontrolled feed back to resin delivery pumps located typically at acontrol station at ground level. Typically, replenishment resin isdelivered to the resin chamber on a continuous basis during eversion ofthe tube structure and is controlled with a feed back loop to controlfeed rate of the everting tube structure and resin pressure forconsistent progress along the conduit.

Preferably, the body also has provision for applying resin to thesurface onto which the tube structure is presented. As alluded toearlier, the surface to which the tube structure is presented maycomprise the interior wall surface of the passageway or a substrateapplied to the interior surface of the conduit.

In this regard, the body may comprise a circumferential chamber which isexposed to the internal surface and which contains resin which is wipedon the internal surface. Where the passageway is of circularcross-section, the circumferential chamber is typically of annularconfiguration.

Preferably, the circumferential chamber is defined between two spacedapart seals and an inner wall extending between the two seals. The outerperiphery of the chamber is essentially defined by the surface to whichthe tube structure is applied.

The seals may comprise wiper seals for sliding and sealing contact withthe surface.

The inner wall may be defined by a flexible membrane. The membrane maybe deflected for the purposes or pressurising the resin contents withinthe chamber. Alternatively and/or additionally, the flexible membranemay be vibrated in order to optimise contact of the resin with thesurface.

The body may further comprise one or more additional chambers oneadjacent another axially spaced along the body.

Each additional chamber may be defined by two seals and an inner wallextending therebetween.

Where there are adjacent chambers, one seal may be common to both of thechambers. In other words, where there are two chambers one leadinganother with respect to the direction of travel of the body, one sealmay function as the trailing seal for one chamber and the leading sealfor the other chamber.

Where there are a multitude of chambers, at least some of the chambersmay be utilised for the purpose of applying resin to the surfacereceiving the tube structure. In such a case, the chambers preferablyoperate at progressively decreasing fluid pressures in the directionaway from the everting tube.

The seals may not only perform a sealing function but also function aswiper applicators for applying the resin in a uniform fashion to theinternal surface.

The chambers may comprise sealed pressurised chambers between which adifferential of pressure can be achieved and maintained, with thehighest pressure being exerted in the rearmost chamber wetting theeverting tube structure and the lowest in the leading chamber. In thisway, purge lines from the rearmost chamber can exhaust into the frontchamber driven by the differential in pressure.

In certain circumstances, it may be beneficial to apply a substrate tothe conduit prior to the placement of the tube structure to provide theliner. Such substrates may include repair and/or sealing compounds (egcementitious or polymer grout) or a layer of material for enhancing theengagement of the tube structure with the conduit or the filling of thesurface of the inside of the conduit.

The substrate substance can be applied in the same pass as the placementof the everting tube structure. Alternatively, the process may involveplacement of the substrate substance first with a removable orsacrificial liner that inflates to hold the substrate substance intoposition whilst it hardens. Then during a second pass the everting tubestructure can be added once the substrate substance has hardened enoughto absorb the water and provide a dry surface to allow the resin to cureto it.

Where a substrate is to be applied to the interior surface of theconduit, at least one of the circumferential chambers may be utilisedfor such a purpose. The or each chamber concerned would be adapted toreceive the substrate substance. The substrate substance would beapplied to the interior surface of the conduit in a similar fashion tothe manner in which resin is applied; that is, the substrate substancewould be presented to and wiped onto the interior surface of theconduit. Obviously, the or each chamber utilised in the installation ofthe substrate would be ahead of the chambers utilised in the delivery ofresin for the purposes of bonding the tube structure into position.

Again, the substrate material may be vibrated to optimise deposition ofthe material onto the interior surface of the conduit.

The body may incorporate a leading section for performing preparatorywork on the interior surface of the conduit in order to properly prepareit to receive the substrate substance or resin as the case may be.

The preparatory work may involve removal of dirt and other matter fromthe surface. For this purpose, the leading section may includecircumferential brush devices adapted to brush the interior wall surfaceof the conduit.

There may be a plurality of the brush devices axially spaced one withrespect to another to form air pressure chambers therebetween. Adifferential pressure gradient may exist between the chambers such thata pressure flow is generated from rearmost chamber to frontmost chamber.

The preparatory work may also involve the application of a preparatorymaterial to the interior surface of the conduit. The preparatorymaterial may comprise a low viscosity adhesive which can be sprayed orotherwise applied.

The forward portion of the apparatus in the preferred embodiment mayalso incorporate a collection means for collecting debris within theconduit prior to installation of the tube structure to provide theliner. The collection means may comprise a suction system for collectingthe debris.

Preferably, the tube structure is delivered to the body in a collapsedcondition. With this arrangement, the collapsed tube structure ispreferably opened during the eversion process.

The tube structure may have a collapsed condition involving at least onere-entrant fold. Conveniently, there are at least two re-entrant foldsone adjacent each longitudinal edge of the collapsed tube structure.

An installation cable (such as a rope) may be provided in the collapsedtube structure for assisting axial movement thereof while in thecollapsed condition. Typically, the cable is used to haul the collapsedtube structure axially. Interaction between the installation cable andthe collapsed tube structure may arise through a binding actiontherebetween as a consequence of the tube structure being collapsedabout the cable. The cable may progressively separate from the tubestructure as the latter everts.

The body may be provided with means to establish a “wet-out” regionwithin the collapsed tube structure prior to eversion thereof for thepurposes of increasing the effectiveness of resin penetration.

This may involve a lance structure projecting outwardly of the contactsurface and terminating at a free end, with the collapsed tube structureembracing the lance structure so that the lance structure is inserted inthe tube structure as it approaches the contact face for eversionthereagainst.

The free end of the lance structure may be configured to spread thecollapsed wall of the tube structure to create a cavity to receive theresin.

To do this reliably, it is preferred to further include means to monitorand/or control the speed of progress of the body and thevolume/thickness of resin applied to the conduit and the everting tubestructure. Such means may be part as a quality control system upon whichthe body may react, or communicate to a remote operator who may provideremote control or through a remote feed back loop to the pressurecontrol to the pumps and the liner pull to vary the speed of advance.This can also control the feed pressure for the resin injection into theeverting tube structure and the inflation pressure of the pressurechamber and the tube structure as well as the vacuum on the tubestructure. In this way, the apparatus can be self controlling to ensurethe optimum rate of progress is maintained. This can then be plotted andthe plot provided to the customer.

The lance may incorporate an axial passage for receiving theinstallation cable as it separates from the tube structure duringeversion thereof.

The apparatus may further include a temperature measurement device formonitoring the temperature of the conduit/liner which may be incommunication with a remote operator. There may also be a feed back loopwith the resin supply to control the amount of catalyst to resin ratioto suit it to the temperature and conditions within the pipe. This mayalso form part of the quality control system.

Preferably, the apparatus further includes means for sensing and/ormonitoring selected conditions associated with installation of the linerand varying the installation process as necessary having regard to suchconditions. Such conditions may include the delivery rate andcomposition of the resin, loadings on the everting tube and the surfacecondition of the conduit.

According to a third aspect of the invention there is provided a methodof lining conduits utilising apparatus according to the first or secondaspects of the invention as set forth above.

According to a fourth aspect of the present invention there is provideda method of lining a conduit comprising: providing a tube structure as aliner for the conduit, everting the tube structure into the conduitwhereby the tube structure has an inner tube portion, an outer tubeportion and an everting portion extending between the inner and outertube portions; causing the exposed face of the everting portion of thetube structure to slidably engage a contact surface at which a curableresin is presented to the everting face for impregnation thereof.

Preferably, the method further comprises sensing and/or monitoringselected conditions associated with installation of the liner andvarying the installation process as necessary in response to suchconditions.

According to a fifth aspect of the invention there is provided a tubestructure characterised in that the tube structure has a collapsedcondition involving at least one re-entrant fold formed therein andextending longitudinally thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood by reference to the followingdescription of several specific embodiments thereof as shown in theaccompanying drawings in which:

FIG. 1 is a schematic sectional view of apparatus according to a firstembodiment in operation installing of a liner in a pipeline;

FIG. 2 is a fragmentary sectional side view of the apparatus installingthe liner in the pipeline;

FIG. 3 is a fragmentary perspective view of the apparatus installing theliner in the pipeline;

FIG. 4 is a fragmentary sectional view of the trailing end of theinstallation head;

FIG. 5 is a fragmentary sectional view of an intermediate part of theinstallation head;

FIG. 6 is a fragmentary sectional view of the leading part of theinstallation head;

FIG. 7 is a fragmentary sectional side view illustrating a wiper sealforming part of the installation head, with the wiper seal being shownin a normal condition;

FIG. 8 is a view similar to FIG. 7 with the exception that the wiperseal is shown in a deflected condition;

FIG. 9 is a schematic cross sectional view of a tube structure whichprovides the liner, the tube being shown in a collapsed condition;

FIG. 10 is a fragmentary sectional view of the trailing end of aninstallation head of apparatus according to a second embodiment;

FIG. 11 is a fragmentary sectional view of the trailing end of theinstallation head of apparatus according to a third embodiment;

FIG. 12 is a fragmentary sectional side view of the trailing end of theinstallation head of apparatus according to a fourth embodiment; and

FIG. 13 is a view somewhat similar to FIG. 12 with the exception that asuction line within the installation head is shown in an extendedcondition;

FIG. 14 is a fragmentary perspective view of apparatus according to afifth embodiment;

FIG. 15 is a perspective view, shown partly cut-away, of a deliverychamber forming part of the apparatus shown in FIG. 14, with thecollapsed tube structure shown passing therethrough;

FIG. 16 is a sectional side view of the delivery chamber shown in FIG.15;

FIG. 17 is a fragmentary view of the apparatus shown in FIG. 14,illustrating guide rollers for guiding the collapsed tube structure;

FIG. 18 is a cross sectional view of a delivery chamber for apparatusaccording to a sixth embodiment;

FIG. 19 is a fragmentary elevational view of apparatus according to aseventh embodiment;

FIG. 20 is a schematic view of a sealing clamping seal mechanism usedwith the apparatus shown in FIG. 19;

FIG. 21 is a schematic view of a suction line incorporated in theapparatus shown in FIG. 20, with the suction line being shown in aretracted condition;

FIG. 22 is a view similar to FIG. 21, with the exception that thesuction line is shown in an extended condition;

FIG. 23 is a schematic end view of a brake slide structure forming partof the apparatus shown in FIG. 20;

FIG. 24 is a view similar to FIG. 23, with the exception that the brakeslide structure is shown on a somewhat larger scale;

FIG. 25 is a side elevational view of the brake slide structure;

FIG. 26 is a schematic side elevational view of apparatus according toan eighth embodiment;

FIG. 27 is a fragmentary perspective view of the apparatus shown in FIG.26 installing a liner in the pipeline;

FIG. 28 is a fragmentary side elevational view of the trailing end ofthe installation head of the apparatus shown in FIG. 26;

FIG. 29 is a view similar to FIG. 28, illustrating the apparatusinstalling a liner without use of a installation cable;

FIG. 30 is a schematic cross sectional view of a tube structure for usewith apparatus according to any of the previous embodiments, the tubestructure being in a collapsed condition having two opposed re-entrantfolds;

FIG. 31 is a schematic view illustrating the everting end of thecollapsed tube structure shown in FIG. 30;

FIG. 32 is a schematic view illustrating, for comparison purposes, theeverting end of a collapsed tube structure of the type illustrated inFIG. 9 of the first embodiment;

FIG. 33 is a schematic cross sectional view of a further version of thetube structure in a collapsed condition having a plurality of opposedre-entrant folds;

FIG. 34 is a schematic cross sectional view of a still further versionof collapsed tube structure;

FIG. 35 is a schematic cross sectional view illustrating the tubestructure of the type shown in FIG. 34 installed within a pipeline toprovide a lining therefor;

FIG. 36 is a schematic cross sectional view of apparatus used fordelivery of the tube structure shown in FIG. 34 to a pipeline;

FIG. 37 is a schematic elevational view of a production system formanufacturing a tube structure of the type shown in FIG. 30;

FIG. 38 is a schematic view of a former used in the system illustratedin FIG. 37;

FIG. 39 is a schematic view illustrating construction of an inner layerof the tube structure;

FIG. 40 is a view illustrating the inner layer folding about the former;

FIG. 41 is a schematic view illustrating construction of an outer layerabout the inner layer to provide the tube structure;

FIG. 42 is a view illustrating the former being used to assemble theouter layer of the tube structure about the inner layer;

FIG. 43 is a schematic plan view of a folding mechanism for performing afolding operation on the tube structure;

FIG. 44 is a schematic plan view of an inner former forming part of thefolding mechanism;

FIG. 45 is a schematic end view of the inner former;

FIG. 46 is a schematic plan view illustrating the folding mechanism inoperation to subject the tube structure to a folding operation;

FIG. 47 is a schematic view illustrating construction of an inner layerof the tube structure with an installation cable therein;

FIG. 48 is a view illustrating the former being used to introduce theinstallation cable into the inner layer of the tube structure duringconstruction thereof;

FIG. 49 is a schematic cross sectional view of an assembly of umbilicalsused for delivery of services to the installation head of apparatusaccording to any of the earlier embodiments, the assembly of umbilicalsbeing contained within a containment sleeve; and

FIG. 50 is a schematic elevational view illustrating assembly of theumbilicals and positioning of the containment sleeve therearound.

BEST MODES(S) FOR CARRYING OUT THE INVENTION

Referring to FIGS. 1 to 9 of the accompanying drawings, there is shownapparatus 10 according to a first embodiment for installing a liner 11onto the interior surface 13 of a pipeline 15. The liner 11 provides ahermetically sealed barrier that is resistant to both corrosion andwear.

In this embodiment, the liner 11 is in the form of an everted tubestructure 17. Prior to eversion, the tube structure 17 comprises a firsttubular layer 17 a of a resin absorbent material such as fibreglassfabric fully or partly impregnated, or dry and a second tubular layer 19providing a membrane. Prior to eversion of the tube structure 17, thefirst layer 17 a is innermost and the second layer 17 b is outermost tosurround the first (inner) layer. The membrane material providing thesecond (outer) layer 17 b is selected according to the demands placed onthe liner 11 within the pipeline 15. For example, where abrasion andwear resistance is required, the second layer 17 b may be formed ofpolypropylene. In other cases, the second layer 17 b may be formed ofpolyester (Mylar), nylon urethane rubber or other material appropriatefor the intended application.

Upon eversion, the first layer 17 a is turned outwardly and presented tothe interior surface 13 of the pipeline 15. As will be explained indetail later, a curable resin is applied to the first layer 17 a priorto its application onto the interior surface 13 of the pipeline 15. Aninflation fluid is delivered into the interior 20 of the everted portionof the tube structure 17 to maintain the tube structure in intimatecontact with the interior surface 13 of the pipeline 15 until the resinhas cured, whereupon the resin and fibreglass fabric combine to providea rigid composite structure which lines the pipeline 15, with the secondlayer 17 b, which provides the membrane, being on the inner face of thecomposite structure and in contact with subsequent fluid flow along thepipeline.

The curable resin may comprise an epoxy, vinyl, polyester or acrylicresin such as methyl methacrylate. The curable resin may be aerated incertain applications.

The apparatus 10 comprises an installation head 21 which is movablealong the pipeline and which includes a body 23. The installation head21 is adapted to be progressively moved along the pipeline 15 duringinstallation of the liner 11.

The body 23 has a leading end 27 and a trailing end 29. In thisembodiment, the body 23 is adapted to be pulled through the pipeline 15by way of a tow line (not shown) connected to the leading end 27 andextending to a station (not shown) located exteriorly of the pipeline.

The tube structure 17 is delivered to, and pulled along, the pipeline 15in a flattened or collapsed condition and is everted from thatcondition, as best seen in FIG. 1 of the drawings. In the flattened orcollapsed condition, the tube structure 17 has two opposed longitudinalside portions 18, 19 and folds 22 therebetween, as shown in FIG. 9. InFIG. 9, the two longitudinal side portions 18, 19 are shown spacedapart, for the purposes of clarity in the drawing. In practice, the twoportions 18, 19 would be in facing contact with each other.

With eversion of the tube structure 17, there is created an inner tubeportion 31 and an outer tube portion 32, with the two portions 31, 32being joined by the everting portion 33.

One end of the tube structure 17 is attached to a rigid installationduct 34 positioned adjacent the inlet end of the pipeline 15. Typically,the tube structure 17 is connected to one end of the duct 34 by way of aclamping collar (not shown) which extends around the tube and sealinglyconnects it to the end of the duct.

A delivery duct 35 extends between the installation duct 34 and adelivery structure 37 which incorporates a delivery chamber 39. Thedelivery duct 35 comprises a flexible hose structure which is inflatedto provide the duct. An inflation chamber 41 is created through thecombination of the interior 20 of the everted tube structure 17, theinstallation duct 34, the delivery duct 35 and the delivery chamber 39.An inflation fluid (such as air) is introduced into the inflationchamber 41 so as to urge the everted tube structure 17 outwardly inorder to position it in contact with the interior surface 13 of the pipe15 to which it is bonded while the resin applied thereto sets.

The inflation fluid is introduced into the inflation chamber 41 by wayof the delivery chamber 39 at the inlet end of the duct 35. The deliverychamber 39 is defined by a housing 43 having an entry end 45 and anoutlet end 47 which communicates with the duct 35. The entry end 45 ofthe delivery chamber 39 is closed to maintain inflation pressure in thechamber, there being provided a fluid seal mechanism 49 in the entry end45 to allow entry of the collapsed tube. The fluid seal mechanism 49comprises a pair of sealing rollers 51 positioned in side-by-siderelationship to receive the collapsed tube structure therebetween. Thesealing rollers 51 are resiliently deformable for the purpose ofestablishing good sealing contact with the tube structure 17.

The inflation pressure causes the tube structure 17 to evert as theinstallation head 21 moves along the pipeline 15.

The installation head 21 has a contact face 63 at the trailing endthereof against which the tube structure 17 everts. The contact face 63is configured to conform to, and guide, the everting portion 33 of thetube structure 17 as it turns between the inner tube portion 31 and theouter tube portion 32. The contact face 63 is defined by a pressureplate 65. A resin chamber 67 is located in the body 23 adjacent thepressure plate 65. The pressure plate 65 provides a boundary for theresin chamber 67 and separates the resin chamber from the everting tubestructure 17. Resin delivery lines 69 are provided for delivering thecurable resin from a source (not shown) to the resin chamber 67.

A plurality of apertures 71 are provided in the pressure plate 65, theapertures 71 extending from the resin chamber 67 and opening onto thecontact face 63 by way of ports 72 incorporated in the contact face 63.With this arrangement, the everting tube structure 17 wipes over thecontact face 63 and so is exposed to resin delivered from the resinchamber 67. The resin from the resin chamber 67 also flows into thespace 68 bounded by the pressure plate 65 and the everting tubestructure 17 to ensure that the everting tube structure is fully exposedto the resin, and travels back down the tube structure to fill and wetthe tube structure as it approaches the pressure plate 65.

A lance structure 73 projects rearwardly from the pressure plate 65 andterminates at a protrusion 74 which is received in the collapsedinterior of the tube structure 17 between side portions 18, 19 as thetube approaches the installation head 21. The protrusion 74 is ofbulbous configuration and incorporates a rounded nose 75 which ispresented to the oncoming collapsed tube structure 17. The protrusion 74serves to expand the collapsed tube wall to create a cavity 76 intowhich resin is delivered by way of delivery ports 77 incorporated in thenose 75 and communicating with a central bore 78 in the lance structure73. The interface between the protrusion 74 and the tube structure 17sliding thereover, provides a seal therebetween. The central bore 78receives resin from the resin supply by way of delivery line 80. Thedesign of the lance structure 73 is such as to provide a base attachedto the pressure plate 65 of small circumference and the protrusion 74 ofa larger circumference. In this way, the lance structure 73 follows thegeneral shape formed by the tube structure as it is everting, with theeverting face itself being the point of highest pressure and the areajust before the everting face being a point of low pressure. Therefore,it is easier to form a cavity just behind the everting face. The cavity76 into which the resin is delivered creates a “wet-out chamber” withinthe collapsed tube structure 17 for the purposes of initially presentingresin to the tube structure. The objective is the creation of a long“wet-out” chamber by the hydraulic force of the resin bulging theeverting tube structure 17. The length and size of the wet-out chambercan be controlled by the resin injection pressure and the inflationpressure within the everting tube structure 17. The balance to beachieved is the length of the wet-out chamber and the wet-out rate. Thelonger the wet-out chamber, the longer time the resin is exposed to thefibreglass the faster the rate of progress.

In the embodiment, the separation of the resin chamber 67 from the forceof the everting tube structure 17 driving and pressing against the rearof the installation head 21 means that the resin pressure need only beenough to fill the depth of the chamber and that this is consistent andcan be monitored. Also the content of resin in the chamber can bemonitored in various means to ensure that all air is purged from theresin volume.

In this embodiment, the installation head 21 further includes a guidestructure 81 about which the tube structure 17 passes as it everts. Theguide structure 81 comprises a guide ring 82 having a ring body 83 witha central opening 84 therein. The ring body 83 presents a guide surface85 about which the tube structure 17 turns, with the inner tube portion31 entering the ring body 83 through the central opening 84 and theeverting portion 33 passing around the guide surface 85 such that theouter tube portion 32 leaves from the outer periphery of the ring body.

The guide structure 81 may be configured to avoid, or at least reduce,the tendency for formation of wrinkles and folds in the tube structure17 as it everts. In this regard, the guide structure may comprise aguide ring structure of the configuration disclosed in PCT/AU01/00563(WO 01/88338).

The guide structure 81 serves to present the tube structure 17, and inparticular first layer 17 a of fibreglass fabric, to the contact face 63for exposure to, and impregnation by, the resin.

The guide structure 81 moves with the body 23 as a result of interactionbetween the protrusion 74 and rollers 93 mounted on a support structure95 extending rearwardly from the ring structure, with the wall of thetube structure 17 passes through the gap 97 between the rollers and theprotrusion 89. Consequently, a pulling force applied to the body 23 byway of the tow line is transmitted to the guide structure 81 so that itmoves in unison with the body 23 by interaction between the protrusion74 and the rollers 93.

The body 23 incorporates a plurality of holding chambers 100 disposedaxially there along. In this embodiment, there are three such holdingchambers 101, 102 and 103.

Each chamber 100 is defined between two spaced apart annular wiper sealsor inflatable spreaders 104 and an inner wall 105. The outer peripheryof each chamber 100 is exposed directly to the interior surface 13 ofthe pipeline 15.

Each inner wall 105 is of flexible construction and can be subjected tovibration for the purposes of pressurising contents of the chamber in apulsating fashion.

An inflatable bladder 106 is associated with each inner wall 105, asbest seen in FIG. 5 of the drawings. Introduction and extraction ofinflation fluid with respect to the inflatable bladder 105 can be usedto generate pulsations in the inner wall 105. Furthermore, the volume ofthe respective chamber 105 can be varied by selective movement of theinner wall 105 under the influence of the inflatable bladder 106.

In this embodiment, each chamber 100 is adapted to receive resin fromthe resin supply or grout form the grout supply for the purposes ofdepositing a layer of resin or grout onto the interior surface 13 of thepipeline 15 prior to application of the liner in position. This furtherensures that there is adequate resin for the purpose of wetting out thefibreglass fabric 17 a.

A particular feature of the flexible wall 105 defining each chamber 101is that the volume of the chamber can be varied and thus regulated, asalluded to above. This is advantageous in that the volume of any one ormore selected chambers 100 can be decreased as the installation head 21approaches the end of the pipeline, thereby ensuring that there islittle or no remnant resin in the chamber at the end of the installationprocess. The presence of remnant resin or grout can cause difficultiesin that it can spill or otherwise be wasted.

The chambers 100 operate at different resin pressures; for example,chamber 101 has a higher resin pressure than chamber 102 which in turnhas a higher resin pressure than chamber 103. The progressivelydecreasing resin pressure extending from chamber 101 down to chamber 103reduces the likelihood of resin leakage from the installation head 21.Any leakage from chamber 101 (which is at the highest resin pressure)can either be rearwardly towards the everting tube structure 17 (whereresin is required in any event) or forwardly into chamber 102 (which isat reduced pressure relative to chamber 101). Similarly, any leakagefrom chamber 102 can either be rearwardly to chamber 101 (which isunlikely owing to the higher pressure in chamber 101) or forwardly tochamber 103 which is at reduced pressure compared to chamber 102.Because chamber 102 is at a reduced pressure, there is little likelihoodof leakage from that chamber. If, however, there is leakage from chamber102 it is unlikely to be of any consequence as it would simply beleakage which deposits resin onto the interior surface 13 of thepipeline 15 where it is required in any event.

The annular seals 104 each comprise a seal face 107 pivotally connectedat hinge 109 to the body 23. The seal face 107 is of annularconfiguration, as is the hinge 109. The hinge 109 is typically a filmhinge.

The seal face 107 is incorporated in an annular seal body 111 which alsoincorporates an annular inflation chamber 113. The seal face 107comprises bristles which are forced outwardly for sliding and sealingengagement with the interior surface 13 of the pipeline 15 uponinflation of chamber 113 as the installation head 21 moves along thepipeline. Because the seal face 107 is biased outwardly, it can followirregularities in the interior surface 13 of the pipeline. When theinflation chambers 113 are deflated, the seals 104 can collapse inwardlyso moving the seal faces 107 away from the interior surface 13 of thepipeline. This is particularly advantageous during initial insertion ofthe installation head 21 into, and removal of the installation headfrom, the pipeline 15. Because the seals 104 are retracted, they do notengage the interior surface 13 of the pipeline 15 and thus facilitateease of travel along the pipe when not in operation and during insertionand removal of the installation head 21. This allows the process to beperformed without interference which otherwise might occur throughengagement of the seals 104 with the interior surface 13 of the pipeline15. Once the installation head 21 is in position in the pipeline 15, thevarious chambers 113 can be inflated so as to move the seal faces 107into sealing engagement with the interior surface 13 of the pipeline 15.

The wipe seals 104 extend rearwardly and outwardly with respect to thedirection of travel of the installation head 21, as is apparent from thedrawings. With this arrangement, the wiper seals 104 are biasedoutwardly into sealing engagement with the interior surface 13 of thepipeline under fluid pressure within the respective chambers 100 towhich the wiper seals are exposed. This is particularly advantageous inrelation to the particular wiper seal confronting the resin chamber 67,as the resin pressure therein serves to urge the wiper seal outwardlyinto sealing engagement with the interior surface of the pipeline.

While the seal and spreader faces 107 have been described as being insliding and sealing engagement with the interior surface 13 of thepipeline, it should be understood that they are more likely to be insliding and sealing engagement with a layer of resin or grout applied tothe interior surface. The seal faces 107 are utilised not only toperform a sealing function but also to perform a wiping or spreadingfunction by applying resin to the interior surface 13. Accordingly, itis necessary for the seal faces 107 to accommodate the film of resin.

In this embodiment, the holding chambers 100 comprise three chambers101, 102 and 103. It will be appreciated that any appropriate number ofchambers can be employed, as necessary. It is particularly advantageousfor there to be a multitude of chambers 100, such that there is ampleresin available to fill defects such as cracks and cavities in theinterior surface 13 of the pipeline 15, with the series of chambersprogressively filling the defects as they pass over them upon movementof the installation head 21 through the pipeline.

The installation head 21 may further comprise a series of axially spacedbrush devices 115 positioned behind the leading end 27 of the body 23.Each brush device 115 comprises an annular base 116 with bristles 117projecting therefrom for brushing engagement with the interior surface13 of the pipeline 15. The brush devices 115 are linked one to anotherby way of flexible cables 118. The brush devices 115 are intended toremove debris from the interior surface 13 of the pipeline 15 in orderto prepare the surface to receive resin for bonding the liner 11 inposition.

A series of chambers 123 are defined between the brush devices 115. Thechambers 123 are adapted to contain air at differential pressure suchthat the air in the trailing chamber is at the highest pressure and theleading chamber at the lowest pressure, with the pressure in theintervening chamber being at an intermediate level such that there is aprogressive increase in air pressure from the trailing chamber to theleading chamber. With this arrangement, a flow of air can be generatedforwardly from one chamber to the next in the event a fault in thepipeline 15 allows air to leak from one chamber to the next. In theprocess of moving from one chamber to the next, the air flow willdislodge debris such as sand and gravel particles and displace waterresting in any cavities of the pipeline 15 by either blowing it out infront of the installation head 21 for collection or, if there is a holein the pipeline 15, by displacing the water and debris through the holeto the outside of the pipeline. In this way, the apparatus 10 can alsooperate in a pipe that is under the water table by displacing the waterby air pressure.

The installation head 21 may further include a collection means 119 forcollecting debris within the pipeline 15 prior to installation of theliner 11. The collection means 119 comprises a suction system having asuction head 120 connected to a suction line 122.

Means (not shown) may also be provided for spraying a low viscosityadhesive onto the interior surface 13 for absorption therein prior toplacement of the liner 11.

The apparatus 10 can be equipped with various sensing and monitoringdevices to facilitate regulation of the installation process for theliner 11, with the objective of establishing and maintaining optimumconditions therefor. Such sensing and monitoring devices may includemeans for conducting visual inspections of the pipeline 15 prior to,during, and/or after the installation process. Additionally, suchdevices may permit a determination to be made as to the extent (if any)of cleaning required for the pipeline surface.

Further, such devices may enable calculation of the optimum volumetricquantities and delivery rates for the resin. In this way, delivery ofthe resin can be controlled to allow application of appropriatequantities. Thus, the delivery rates (and hence volume) of resin can beregulated on an ongoing basis during the installation process where, forexample, it may be necessary to apply more resin at some locations thanat other locations because of variations in the pipeline condition alongits length. As well as avoiding wastage of resin, this may also allowthe installation speed to be increased at locations where reduced resinquantities are required.

Still further, the sensing and monitoring devices may allow optimumcuring conditions for the resin to be determined, having regard tofactors such as, for example, temperature and humidity. This may permitthe composition of the resin to be varied as necessary in an endeavourto provide optimum curing conditions, by for example adding, removing orvarying the quantity of components such as accelerators, activatorsand/or catalysts.

Other sensing and monitoring devices may include sensors for measuringthe strain and load on the everting liner.

The use of the sensing and monitoring devices facilitates ongoing, or atleast regular, feedback for maintenance of optimum installationconditions. This enhances the reliability of the installation process.

The installation head 21 is of articulated construction so that it cannegotiate contours and bends within the pipeline. The flexible nature ofthe cables 118 extending between the brush devices and sliding sealsspreaders and scrapers 115 facilitates the articulated construction ofthe installation head 21.

Operation of the apparatus 10 installing the liner 11 in the pipeline 15will now be described.

The installation head 21 is positioned within the pipeline 15 adjacentthe end thereof at which the lining operation is to commence. Theleading end 27 of the body 23 is connected to a tow line which extendsto the other end of the pipeline and terminates at a station at whichvarious operations are performed including retraction of the tow line inorder to pull the installation head 21 along the pipeline. Theinstallation duct 34 is positioned adjacent the commencement end of thepipeline 15 and the delivery structure 37 is installed at a convenientlocation, typically at ground level in the vicinity of the end of thepipeline. The delivery duct 35 is then positioned between theinstallation duct 34 and the delivery structure 37. Because of itsflexible nature, the delivery duct 35 can conveniently follow an accesspath dug in the ground leading to the end of the pipeline. The tubestructure 17 is then passed in a collapsed condition through the entryend 45 of the delivery chamber 39 within the delivery structure 37 andalong the delivery duct 35 to project beyond the installation duct 34.The leading end of the collapsed tube structure 17 is then connected tothe installation duct 34 by way of a clamping collar which extendsaround the tube and sealingly connects it to the end of the duct 34.Fluid pressure is then introduced into the delivery chamber 39 and thedelivery duct 35, so as to inflate the delivery duct 35 and commenceeversion of the tube structure 17. The fluid pressure is generated byintroduction of an inflation fluid, typically air. As the tube structure17 commences to evert, its everting portion 33 is presented to, andguided into the end of the pipeline 15 so that the tube structureadvances along the pipeline as it everts.

As the everting tube structure 17 advances along the pipeline 15, itembraces the lance structure 73, and the everting portion 33 engages thepressure plate 65 at the trailing end of the body 23. The rate ofadvancement of the everting tube structure 17 along the pipeline 15 iscontrolled by the rate at which the installation head 21 itself travels,with the everting face 33 of the tube structure 17 being in wipingcontact with the contact face 63. Because the contact pressure exertedby the everting tube structure 17 is directed primarily onto thepressure plate 65, the resin itself can flow freely through theapertures 71 and into the space bounded by the pressure plate 65 and theeverting portion 33 of the tube structure 17. Resin within the resinchamber 67 passes through the apertures 71 in the pressure plate 65 andso contacts the everting portion of the tube structure 17 to impregnatethe fibreglass layer thereof. The fibreglass layer 17 a is also wettedwith resin through exposure to resin at the nose 75 of the lance 73. Asthe installation head 21 advances along the pipeline 15, resin isapplied to the interior surface 13 of the pipeline by way of thechambers 100. The wiper seals 104 function as wipers or scrapers forspreading the resin in a uniform fashion on the interior surface 13.

Because of the various locations at which resin is presented to thefibreglass layer 17 a of the tube structure 17 by the time it contactsthe interior surface 13 of the pipeline 15, optimum resin impregnationof the fibreglass fabric is achieved.

Inflation pressure within the everting tube structure 17 presses theouter portion 32 of the tube structure 17 into intimate contact with theinterior surface 13 of the pipeline 15. The process continues until theinstallation head 21 reaches the other end of the pipeline 15, where itcan be withdrawn from the pipeline and the surplus end section of thetube structure 17 clamped to the pipeline 15 so as to close the end ofthe inflation chamber 41 and thereby maintain inflation pressure withinthe everted tube structure 17 until such time as the resin sets to forma composite structure in co-operation with the fibreglass fabric.

It is desirable to avoid spillage of resin once the installation head 21reaches the end of the pipeline 15, as such spillage can be both messyand wasteful. With a view to avoiding, or at least reducing, resinspillage, the supply of resin to the resin chambers 100 can be regulatedas the installation head 21 approaches the end so that only thenecessary quantity of resin is contained within the chambers and thereis little or no surplus resin remaining on arrival at the pipeline end.

The surplus end section of the tube structure 17 may be clamped in anyappropriate way. One particularly suitable way involves a clampstructure (not shown) having a base and a flexible clamping strapattached at one end thereof to the base. The clamping strap can beconfigured into a loop around the surplus end section of the tubestructure and the opposite end of the clamping strap connected to amechanism mounted on the base and operable to cause constriction of theloop. The mechanism may, for example, comprise a winding mechanism aboutwhich the strap can be wound.

Such a clamp structure provides a simple yet highly effective clampingarrangement. All that is required is to loop the strap around the tubestructure end section, connect the free end of the strap to the windingmechanism, and then operate the mechanism to cause constriction of theloop and thus clamping of the tube structure.

It is a feature of the apparatus 10 that a mass of resin is constrainedwithin the resin chamber 67. In particular, the mass of resin isconstrained at one end thereof by the body 23 where it confronts aresistive force presented thereby. The mass of resin is also constrainedat the other end thereof by the everting portion 33 of the tubestructure where it is exposed to a pushing or driving force presentedthereby. In other words, the mass of resin is constrained by forcesexerted on it by the body 23 and the everting tube structure 17. Suchforces act on the mass of resin such that it is in effect a column ofresin ahead of the everting tube structure 17.

In this embodiment, the wiper seals 104 perform both sealing and resinspreading functions. It should be understood that such functions can beperformed by separated elements, if desired. For example, a mechanicaltrowel may be provided to perform, or assist in performing, thespreading function.

In the first embodiment, there was a mechanical connection between thebody 23 and the guide structure 81 by virtue of interaction between theprotrusion 74 and rollers 93 for the purposes of moving the guide ringstructure 81 along the pipeline 15 in unison with the body 23.

In an alternative arrangement, there is may be an electromagneticconnection between the body 23 and the guide structure 81 for suchpurpose. The electromagnetic interconnection may be the sole connectiontherebetween or it may be augment a mechanical connection of anyappropriate type such as that described in relation to the firstembodiment.

The second embodiment, which is illustrated in FIG. 10 of the drawings,uses an electromagnetic connection between the body 23 and the guidestructure 81. The electromagnetic connection comprises an electromagnet121 positioned on the pressure plate 65 on the side thereof opposite thecontact face 63. With this arrangement, the electromagnet 121 isaccommodated within the resin chamber 67. The electromagnet 121incorporates apertures 123 which align with corresponding apertures 71in the pressure plate 65 so as not to interfere with flow of resin fromthe resin chamber 67 to the contact face 63.

A particular advantage of the electromagnetic connection is that the gapbetween the contact face 63 and the guide surface 85 of the guidestructure 81 can be selectively varied by virtue of the intensity of themagnetic field which is established. In this way, the drag imposed onthe tube 13 by the installation head 21 as it advances along thepassageway 15 can be regulated. This information can be incorporatedinto a direct feed back loop so that the process and the thickness ofthe resin contained between the face and the ring can be controlled.

In this embodiment, the installation head is equipped not only with theelectromagnetic connection but also the mechanical connection providedby interaction between the rollers 93 supported on the guide structure81 and the protrusion 73 provided on the lance 73 projecting rearwardlyfrom the body 23. In this way, the connection between the guide ring 81and the body 23 is maintained even when the electromagnetic connectionceases.

In the first and second embodiments, the tube structure 17 everts arounda guide structure 81. It should, however, be appreciated that the guidestructure may not be necessary in certain applications. The action offluid pressure within the everting tube structure 17 may be sufficientto cause eversion of the tube structure and to advance the tubestructure along the pipeline. The rate of advancement of the evertingtube along the pipeline is controlled by the rate at which theinstallation head 21 itself travels, with the everting face 33 of thetube structure 17 being in wiping contact with the contact face 63. Suchan embodiment is illustrated in FIG. 11 of the drawings.

In this embodiment, the tube structure 17 is not physically connected tothe installation head 21 in a manner whereby it can be drawn along bythe installation head. Rather, the tube structure 17 merely bears on theinstallation head through contact therewith at the contact face 63 ofthe pressure plate 65. Additionally, the tube structure 17 embraces thelance 73 in the manner previously described in relation to earlierembodiments.

It will be understood that contact between the everting portion 33 ofthe tube structure and the contact face 63 may be indirect contact inthat there is a film of resin therebetween.

The installation head 21 may be equipped with a mechanism 130 forextracting air from cavities which might exist on the upper part of thetop part of the interior surface 13 of the pipeline. Such an arrangementis incorporated in the embodiment illustrated in FIGS. 12 and 13 andincludes a suction line 131 having a suction end 133. The suction line131 adjacent the suction end 133 is configured at 135 to function as aspring arrangement biasing the suction end to an outermost conditionprojecting beyond the periphery of the body so as to be capable ofentering cavities in the top section of the pipeline 15, as illustratedin FIG. 13 where it is seen that the suction end 133 has entered cavity139. Normally, the suction end 133 is retained in a retracted conditionas shown in FIG. 12, by virtue of contact with the interior surface 13of the pipeline 15. However, when the suction end 133 encounters acavity (such as cavity 139 as shown in FIG. 13), the suction end 133 canproject outwardly and enter the cavity.

The suction end 33 is slightly offset from normal to the surface 13 ofthe pipeline, with the orientation being away from the direction ofmovement of the installation head, so as to avoid jarring or catching onthe pipeline surface 13.

Referring now to FIGS. 14 to 17, there is shown apparatus 10 accordingto a further embodiment for installing a liner 11 onto the interiorsurface 13 of a pipeline 15.

The apparatus according to this embodiment is similar to the apparatus10 according to the first embodiment, and so corresponding referencenumerals are used to identify corresponding parts, where appropriate. Inthis embodiment, the delivery chamber 39 incorporates guide rollers 141against which the collapsed tube structure 17 engages. The guide rollers141 assist tracking of the tube structure 17 as it enters the deliveryduct 35.

A roller assembly 143 is provided adjacent the end of the delivery duct35 for the purposes of aligning the tube structure prior to entrythereof into the installation duct 34. The roller structure 143comprises a pair of rollers 145 between which the collapsed tubestructure 17 passes, with the longitudinal side portions 18, 19 of thecollapsed tube structure in engagement with the rollers 145. The rollerassembly 143 incorporates a lateral guide roller 147 against which oneof the longitudinal edges of the collapsed tube structure 17 engages.The guide roller 143 assembly assists with lateral tracking of thecollapsed tube structure as it enters the installation duct 34.

Referring now to FIG. 18 of the drawings, there is shown a deliverychamber 39 for an installation apparatus according to a still furtherembodiment. The delivery chamber 39 for this embodiment is similar tothe delivery chamber of the previous embodiments, with the exceptionthat it incorporates two fluid seal mechanisms 49, rather than one suchfluid seal mechanism as was the case with the earlier embodiment.

Referring now to FIGS. 19 to 25 of the drawings, there is showninstallation apparatus 10 according to a still further embodiment.Again, where similarities exist with earlier embodiments, correspondingreference numerals are used to identify corresponding parts. Theinstallation apparatus 10 according to this embodiment comprises aninstallation head 21 somewhat similar to the installation head of thefirst embodiment. In the first embodiment, the installation head 21 wasdescribed as being drawn along the pipeline 15 by a towline. In certainapplications, the installation head 21 may be advanced not by a towlinebut rather by a driving force applied to it by the everting tubestructure 17. Specifically, inflation fluid pressure, which isintroduced into chamber 20 within the tube structure for causingeversion thereof and also for pressing the outer portion 32 of the tubestructure into intimate contact with interior surface 13 of the pipeline15, may be sufficient to apply a driving force to the installation head21 through the pressure plate 65 which the everting tube structure 17contacts. In such circumstances, there may be a need to have a mechanismfor retarding the rate at which the installation head 21 advances underthe influence of the fluid pressure applied through the everting tubestructure 17. For this purpose, the installation head 21 according tothis embodiment incorporates a brake sled 151. The brake sled 151 islocated ahead of the installation head 21 and is connected thereto byway of a rigid coupling 153 for transference of a retarding force fromthe brake sled 151 to the installation head 21.

The brake sled 151 is adapted to frictionally engage the interiorsurface 13 of the pipeline 15 so as to provide the retarding force. Theretarding force can be selectively varied by regulating the extent offrictional engagement with the interior surface 13 of the pipeline 15,as will be explained shortly. Furthermore, the retarding force is alsoregulated by having a mechanism for driving the brake sled 151, thearrangement being that the rate of advancement of the brake sled 151(and hence the installation head 21 to which it is rigidly coupled) canbe controlled by selectively varying the driving force applied to thebrake sled. In other words, the rate at which the brake sled 151 andinstallation head 121 advance in unison is determined by a balancebetween: (1) the force applied to the installation head 21 through theeverting tube structure 17 by the inflation fluid; (2) the driving forceapplied to the brake sled; and (3) the retarding force exerted on thebrake sled 151 through frictional engagement with the pipeline 15.

In this embodiment, the brake sled 151 is driven by applying a towingforce thereto through a towline 157, one end of which is coupled to thebrake sled at coupling point 158 and the other of which is connected toa hauling mechanism such as a winch (not shown).

The brake sled 151 comprises three skid members 161, 162 and 163, eachadapted to be located in sliding engagement with the interior surface 13of the pipeline 15. Skid member 161 functions as the base of the brakestructure 151 and travels along the bottom of the pipeline 15. The skidmembers 162 and 163 are supported on base skid member 161 by booms 165,167. Boom 165 incorporates an adjustment mechanism 169 for selectivelyvarying the effective length thereof and thus the relative position ofskid member 162. In this way, the spacing between the three skid members161, 162 and 163 can be varied, thus regulating the radial positioningof the skid members and consequently the force with which theyfrictionally engage the interior surface 13 of the pipeline 15.

In this embodiment, base skid member 161 comprises a tubular member 171filled with ballast material such as lead. The leading end of thetubular member is upturned, and a longitudinal web 173 is provided alongthe length of the tubular member.

Skid members 162, 163 each comprise an elongate element 175 beingin-turned at the leading end thereof. Each elongate element 175 isprovided with a covering 177 formed of friction material (such as tyretread) for the purpose of enhancing frictional resistance with theinterior surface 13 of the pipeline 15.

The installation head 21 according to the embodiment also incorporates asuction mechanism 130 for extracting air from cavities which might existon the upper part of the interior surface 13 of the pipeline 15, as wasthe case with the first embodiment. The suction mechanism 130 in thisembodiment comprises a suction line 181 having a suction end 183. Thesuction line 181 adjacent the suction end 183 incorporates a formation185 which causes the outer end section 187 of the suction line 181 todeflect laterally to extend beyond the periphery of the installationhead so as to be capable of entering cavities in the upper part of thepipeline 15, as shown in FIG. 22 of the drawings where the end section187 is shown in cavity 188. The formation 185 in the suction line 181establishes a “kink” in the suction line 181 when the outer section 187is not deflected laterally, as shown in FIG. 21 of the drawings. The“kink” functions as a valve for the purposes of stopping, or at leastretarding, flow into the suction line 181 in circumstances where airextraction is not necessary (ie. where there is no cavity).

This embodiment also incorporates the feature of a clamping sealmechanism 191 for clampingly retaining the outer tube portion 32 insealing engagement with the interior surface of the pipeline 15. This isfor the purpose of blocking rearward flow of resin to ensure that thereis an ample coating of resin between the interior surface 13 of thepipeline 15 and the outer tube portion 32 in the section 193 thereofimmediately rearward of the everting portion 33 of the tube structure17. With this arrangement, the resin is contained at one end by theclamping seal mechanism 191 and at the other end by the pressure plate65 and the annular seal 104 therearound. This ensures that there isample resin between the interior surface of the pipeline 15 and thesection 193 of the liner rearward of the everting portion 33 for bondingpurposes.

The clamping seal mechanism 191 comprises a support 194 of split ringconstruction, incorporating a mechanism 196 for expanding andcontracting the ring. The outer surface of the support 194 is providedwith a layer 198 of deformable material, such as rubber, for thepurposes of accommodating irregularities in the surface against which itbears. The split-ring support 194 is moved into a contracted conditionso as to allow it to be fitted in position in the pipeline 15. It isthen expanded to clampingly engage against the interior surface of thepipeline 15, with the outer tube portion 32 clamped therebetween.

In the installation head 21 used in the first embodiment, the pressureplate 65 defining the contact face 63 was rigidly supported within theinstallation head. In this embodiment, the pressure plate 65 issupported on an elastic suspension system 201 incorporating a spring203. This allows the pressure exerted on the pressure plate 65 throughthe everting tube portion 33 by the inflation fluid to be monitored andoperating systems adjusted accordingly. For example, the rate ofdelivery of resin to the resin chamber 67 can be varied by regulatingthe resin delivery pump according to operating demands as determined bythe pressure. In this embodiment, this arrangement involves use of aproximity switch (not shown) which detects deflection of the pressureplate 65 to a prescribed extent in response to pressure exerted thereon,so as to initiate delivery of resin to the resin chamber 67. In thisway, delivery of resin to the resin chamber 67 can be stopped, or atleast reduced, in the event of separation between the contact face 63 ofthe pressure plate 65 and the everting portion 33 of the tube structure17. The resin flow can recommence once the everting portion 33 of thetube structure 17 moves into appropriate contact with the contact face63, as determined by deflection of the pressure plate 65.

The embodiment shown in FIGS. 26, 27 and 28 is directed to apparatus 10according to a still further embodiment for installing a liner 11 ontothe interior surface 13 of a pipeline 15. The apparatus 10 according tothis embodiment is similar in most respects to the apparatus 10according to the first embodiment and corresponding reference numeralsare used to identify corresponding parts. In this embodiment, there isprovision for hauling the collapsed tube structure 17 along the deliveryduct 35 and installation duct 34, as well as the pipeline 15, to augmentthe advancing movement effected by the inflation pressure.

The haulage system utilises an installation cable 211 in the form of ahaul rope. The haul rope 211 extends axially through the tube structure17, such that the tube structure binds to the rope when the tubestructure is in its collapsed condition. While not apparent from thedrawings, in this embodiment the tube structure comprises an inner layer17 a and an outer layer 17 b, with the rope 211 extending axially alongthe tube structure within the inner 211 layer. The rope 211 is insertedinto position in the tube structure 17 at the time of manufacture of thetube structure 17.

The rope 211 is hauled by an appropriate hauling mechanism, such as awinch or winding drum (now shown).

In this embodiment, the lance 73 projecting rearwardly from the pressureplate 65 terminates at protrusion 74 which is of generally sphericalconfiguration. It may be advantageous for the lance 73 to have somelateral flexibility. The protrusion 74 is received in the collapsedinterior of the tube structure 17 between the longitudinal side portions18, 19 thereof as the tube structure approaches the installation head.The lance 73 has a passage 221 extending axially therethrough. Thepassage 221 is dimensioned to receive the rope 211 with a clearancespace 223 therebetween, as best seen in FIG. 28 of the drawings. Withthis arrangement, the lance 73 assists in separating the haul rope 211from the collapsed tube structure 17, with the rope 211 passing throughthe lance structure 73 and the longitudinal portions 18, 19 moving toopposed sides of the lance as they approach the contact face 63 of thepressure plate 65, also as best seen in FIG. 28 of the drawings.

The clearance space 223 provides a passage through which any air withinthe collapsed tube structure 17 can escape.

The seal established at the interface between the protrusion 74 and thetube structure 17 sliding thereover, prevents migration of resin fromthe resin chamber 67 and the region around the lance 73 beyond theprotrusion 74 and into contact with the haul rope 211 and also into thepassage 221. Presence of resin on the haul rope 211 and in the passage221 would be most undesirable, as it could impede separation of the haulrope from the tube structure 17 and also movement of the haul rope alongthe passage 221.

Because the collapsed tube structure 17 binds to the rope 211 and isseparated therefrom through interaction with the lance 73, the haul ropeand tube structure advance at the same rate along the delivery duct 35and installation duct 34.

Because the haul rope 211 is drawn through the central passage 221within the lance 73 and is connected to a hauling mechanism such as awinch, it moves independently of the installation head 21.

While the embodiment shown in FIGS. 26, 27 and 28 is designedspecifically for use with a tube structure 17 incorporating a haul rope211, it can also be used with a tube structure which does notincorporate such a haul rope. Use of the installation head according tothe embodiment with a tube structure 17 without a haul rope isillustrated in FIG. 29 of the drawings.

In the embodiments described previously, the tube structure 17 wasdelivered to installation head 21 in a collapsed condition as shown inFIG. 9 of the drawings.

It has been found that there is an advantage in folding the tubestructure 17 into a collapsed condition involving one or more re-entrantfolds. Such a folded condition is illustrated in FIG. 30 of thedrawings, where the tube structure 17 comprises an inner tubular layer17 a and an outer tubular layer 17 b. In this embodiment, the innertubular layer 17 a is of a resin absorbent material such as fibreglassfabric, and the outer tubular layer 17 b is of a material appropriatefor the intended purpose, such as polypropylene.

The tube structure 17 is folded into a collapsed condition involving twore-entrant folds 231, 232 disposed between two longitudinal sideportions 18, 19. With this arrangement, the re-entrant folds each extendinwardly from one longitudinal edge of the collapsed tube structure.Again, it should be noted that the longitudinal portions 18, 19 areillustrated in FIG. 30 in a spaced apart condition, however, in practicethey would be in facing contact.

Such a folding structure has been found to be particularly advantageousin the manner in which it undergoes eversion. This will be explainedwith reference to FIGS. 31 and 32, where FIG. 31 is a schematic view ofthe everting portion 33 of the collapsed tube structure shown in FIG.30, and FIG. 31 is a view of the everting portion of the collapsed tubestructure shown in FIG. 9. It can be seen from FIG. 31 that the tubestructure 17 everts in a nearly even manner, with imaginary chords 235along the surface 237 of the everting portion travelling about the samedistance and in a relatively even direction radially in moving from thecollapsed condition to the assembled condition. By comparison, it isevident from FIG. 32 that the collapsed tube structure shown in FIG. 13does not evert in such an even fashion.

The collapsed tube structure 17 shown in FIG. 30 has two re-entrantfolds 231, 232. It should be appreciated that other folding patternsinvolving re-entrant folds are possible. For example, FIG. 33illustrates a collapsed tube structure 17 involving a plurality ofre-entrant folds 231, 232 extending inwardly from the longitudinal edgesthereof.

Another folding pattern, which is not illustrated, may involve radiallyextending re-entrant folds circumferentially spaced around the tubestructure. In such a case, the collapsed tube structure would have asomewhat star configuration.

Referring now to FIGS. 34, 35 and 36, there is shown a construction ofthe tube structure 17 having provision for extraction of air containedtherein. The arrangement comprises a sleeve 241 formed of a flexibleplastic material or any other appropriate material impermeable to air.The sleeve 241 encases the collapsed tube structure 17. FIG. 34illustrates the arrangement in a very schematic fashion which does nottruly resemble the actual appearance. In reality, the tube structure 17is collapsed such that the longitudinal portions 18, 19 are pressed oneagainst the other in facing contact, with the re-entrant foldscompressed therebetween. Furthermore, the sleeve 241 tightly encases thecollapsed tube structure 17. Longitudinal spacer elements 243 extendaxially along the collapsed tube structure 17 between longitudinalportion 18 and the encasing sleeve 241.

In one arrangement, the longitudinal elements 243 comprise a bundle offibreglass strands. The longitudinal elements 243 cooperate with thecollapsed tube structure and the encasing sleeve to establish an axialpath 247 along which air can be extracted. Typically, the axial air path247 is established with the bundle of fibreglass strands. The axial path247 communicates with suction source (not shown) at the trailing end ofthe collapsed tube structure 17.

In another arrangement, the longitudinal elements 243 comprise flexibletubes defining paths for extraction of air, with the tube side wallsbeing perforated at appropriate locations for air ingress. As with thefirst arrangement, the tubes communicate with a suction source or toatmosphere.

As shown in FIG. 35, the collapsed tube structure 17 is delivered from areel 251 about which it is wound. The reel 251 has provision 253 forcoupling the end of the air path 247 to the suction source.

Various embodiments described previously utilise a tube structure 17having an inner layer 17 a and an outer layer 17 b. FIGS. 37 to 48 ofthe drawings illustrate an arrangement for conveniently constructingsuch a tube structure 17.

The arrangement comprises an assembly line 250 at which variousoperations of the construction process can be performed. The assemblyline 250 has a first end 251, a second end 252, and a construction pathextending between the first and second ends. At the first end 251,various materials used in the construction process can be delivered tothe construction path from respective reels on which the materials aresupplied. At the second end 253, the constructed component can be woundonto a storage reel 257. The storage reel 257 is driven to facilitatewinding of the component thereonto.

The construction path has various operational stages, comprising a firstforming stage 261, a second forming stage 262, a third bonding stage 263and a fourth folding and pressing stage 264. In this embodiment, thesecond and third stages 262, 263 are integrated in a single unit 267.

The first stage 261 involves a former 269, as shown in FIG. 38 of thedrawings. The former 269 comprises a outer member 271 incorporating anaperture 273 located therein. A loop member 275 is accommodated withinthe aperture 273 in spaced apart relationship from the peripherythereof, such that there are two working spaces 281, 282 defined withinthe former 269. The space 281 is defined between the outer member 271and the loop member 275, and the space 282 is defined within theconfines of the loop member 275, as shown in FIG. 37.

Construction of the inner layer 17 a of the tube structure 17 will nowbe described with reference to FIGS. 39 and 40 of the drawings. A roll290 of fibreglass material is located at the first end 251 and a web 291of material therefrom is fed along the construction path, passing in theouter space 281 within the former 269, as shown in FIG. 40 of thedrawings. In this way, the longitudinal edge portions of the web 291 offibreglass material are turned inwardly towards each other, in the firststep of the process of forming the web into a tubular configuration.From the first former 269, the web 291 (with the longitudinal sidesthereof turned inwardly) continues to travel along the construction pathtowards a second former at second stage 262 at which the longitudinaledges are positioned one with respect to the other for bonding together.The bonding action is performed at the third bonding stage 263. Forconstruction of the inner layer 17 a, the bonding process typicallyinvolves adhesive bonding. This completes construction of the innerportion in its tubular form, and it is then wound onto a storage reel293 at the second end 252.

The next stage of the process involves transferring the reel 293 onwhich the inner layer 17 a is wound to the first station 251. A web 295of material for the outer layer 17 b is to be constructed on a reel 297also at the first station. The tubular inner layer 17 a is fed into theinner space 282 within the former 269, and the web 295 of material toprovide the outer layer 17 b is fed into the outer space 281 within theformer 269, as best shown in FIG. 42. As the materials travel throughthe former 269, the longitudinal side portions of the web 295 containedwithin the outer space 281 are turned inwardly to commence constructionof the outer layer 17 b in its tubular configuration. From the firstformer, the materials travel to the second former at station 262 atwhich the longitudinal edges of the web 295 are brought together andbonded one to another so as to complete construction of the outer layer17 b in its tubular configuration. This thus provides the tube structure17 having the inner and outer portions. The bonding process inconstruction of the outer layer 17 b typically involves plastic welding.

Where the tube structure 17 is to have a collapsed configuration asshown in FIG. 9, the construction process continues to stage 264 wherethe collapsed tube structure is compressed to ensure that bondedsurfaces are in good contact one with the other and to also flatten thetube structure to facilitate winding onto a reel 299 at the secondstation.

In circumstances where the tube structure 17 is to have re-entrantfolds, such as illustrated in FIGS. 30 and 33, the tube structure 17 issubjected to a folding operation. This can be conducted prior to windingof the tube structure onto the reel 299, or alternatively as a separateoperation at a later stage.

The folding operation may be performed using a folding mechanism 301 asillustrated in FIGS. 43 to 46 of the drawings. The folding mechanism 301comprises an inner former 302 and a cooperating outer former 303. Thearrangement is that the inner former 302 is positioned within thetubular structure 17 and the outer former 303 cooperates with the innerformer to form the re-entrant folds 231, 232.

The inner former 302 comprises a body 304 having two opposedlongitudinal sides 305, with a longitudinal channel 306 opening ontoeach side 305 and a central web 307 therebetween, as best seen in FIG.45. With this arrangement, each channel 306 provides a recess into whicha portion of the tubular structure 17 can be pressed to form therespective re-entrant fold.

The outer former 303 comprises a body 308 having a pair of press wheels309 in spaced apart relationship, the spacing being slightly larger thanthe central web 307 defined between the two channels 306 in the innerformer 302.

With this arrangement, the outer former 303 is positioned around theinner former 302, with the press wheels 309 received within the channels306 and portions of the tubular structure 17 interposed therebetween.Relative movement of the inner and outer formers 302, 303 with respectto the tube structure 17 causes the press wheels 309 to press portionsof the tube structure 17 into the recesses 306 and thereby progressivelycreate the re-entrant folds.

Relative movement between the folding mechanism 301 and the tubestructure 17 can be achieved in any appropriate way. For example, theinner former 302 may be hauled along the interior of the tube structure17, with the outer former 303 moving along the tube structure in unisonwith the inner former. The inner former may be hauled in any appropriateway, such as by a cable 300 attached thereto.

In another arrangement, the folding mechanism 301 may be located at afolding station and the tube structure 17 progressively advanced throughthe folding station to undergo the folding operation.

Once folded the folds can be held in position by some appropriate meansduring storage and handling. The means of restraint are removed upon thetube structure being introduced into the rollers of the pressure chamberand are held in a collapsed position by the pressure within the chamberand the pipe as it moves down to and everts at the eversion point.

Where the tube structure 17 incorporates a haul rope 211 as describedearlier in relation to the embodiment shown in FIGS. 26, 27 and 28, thehaul rope 211 can be incorporated into the tube structure 17 duringconstruction thereof. Specifically, the haul rope 211 can be positionedwithin the inner tubular layer 17 a during its construction. This can beseen with reference to FIGS. 47 and 48 of the drawings, whichillustrates construction of the inner layer 17 a. The rope 211 isprovided on a reel 309 and is fed into the inner space 282 within thefirst former 269, with the web 291 of material providing the inner layer17 a passing through the outer space 281, as shown in FIG. 48. In thisway, the inner layer 17 a is formed around the rope 211.

It is likely that the installation heads 21 according to the previousembodiments will require a plurality of service lines 310 for provisionof services such as electrical power, resin supplies, and a winchingcable, as shown in FIG. 50. The service lines 310 extend to theinstallation head 21 from a station 311 located exteriorly of thepipeline at the end thereof which the installation head 21 approachesduring the lining operation. The station 311 accesses the undergroundpipeline 15 by way of access hole 313 in the ground 315. As theinstallation head 21 approaches the end, the necessary length of eachservice line progressively reduces and so surplus service line is woundonto reels. In certain circumstances, it may be advantageous to containthat lengths of the surface lines within the pipeline within acontainment sleeve 320, for the purposes of avoiding tangling and otherinterference between the various surface lines. This can be achieved byway of the containment sleeve 320 as illustrated in FIG. 49 of thedrawings. The containment sleeve 320 may be formed of a plurality ofsleeve sections 321 adapted to be zipped one to another by zippers 323to form the containment sleeve. The sleeve sections 321 can beprogressively unzipped as the sleeve 320 approaches the station 311,thereby allowing the various service lines 310 to separate for windingonto their respective reels 311. The containment sleeve 320 constructedof sleeve sections zipped together may be in the form of a shroud of thetype described in U.S. Pat. No. 6,196,766. The haul rope 211 (ifemployed) is not accommodated in the containment sleeve 320.

In the various embodiments described, each chamber 123 was adapted tocontain air. In an alternative embodiment, the trailing chamber 123 maybe adapted to receive and contain nitrogen (or another appropriate gasor gaseous mixture) to displace air and thus provide an inertenvironment to which the resin is exposed as it is subsequently applied.

In the embodiments described, the liner has been applied directly to theinterior surface 13 of the pipeline 15. There may be circumstances whereit is beneficial to apply a substrate to the interior surface 13 of thepipeline 15 prior to placement of the liner. This can be particularlyadvantageous in circumstances where the interior surface is in a badstate of repair. The substrate may include repair and/or sealingcompounds or a layer of material for enhancing the engagement of theliner with the interior surface 13.

Where a substrate is to be applied to the interior surface 13,additional holding chambers 100 are provided for such a purpose. Thesubstrate substance would be applied to the interior surface 13 of thepipeline in a similar fashion to the manner in which resin is applied;that is, the substrate would be presented to and wiped onto the interiorsurface 13 of the pipeline 15. The or each additional chamber used inthe installation of the substrate would, of course, need to be ahead ofthe chambers utilised for the delivery of resin for the purposes ofbonding the liner in position. The substrate material may be vibrated inorder to optimise its deposition onto the interior surface of thepipeline.

The substrate material may be aerated.

In certain applications, it may be useful for the holding chambers 100to be divided into segments (for example, an upper segment and a lowersegment), with the segments containing resin of differentcharacteristics. There may, for example, be situations where it isdesirable to have the upper region of the rigid liner constructed usingresin which provides one characteristic to that region, and a lowerregion constructed using another resin to provide that region with adifferent characteristic. This may be useful in a situation where thelower region of a liner needs to have good wear resistancecharacteristics and the upper region is required to have resistance tothe corrosive effects of gases contained within the pipeline.

In the embodiments described previously, the lining applied by apparatusaccording to the various embodiments comprise a liner extendingcontinuously along the length of the pipeline or at least along anextended portion of the pipeline. There may be occasions where there islocalised deterioration of a pipeline which does not necessitate thatthe entire length of the pipeline, or an extended section of thepipeline length, be lined. In such circumstances, it may be advantageousto merely patch localised areas within the pipeline. This can beachieved by forming the tube structure as a membrane with one or morediscrete liner portions of resin absorbent material positioned thereonat appropriate locations such that upon eversion of the tube structurethe portions of resin absorbent material are applied to the internalsurface of the conduit at locations where patching is required. Withthis arrangement, the tube structure is somewhat similar to the tubestructure of previous embodiments in that it comprises inner and outerlayers, with the exception that the inner layer is releaseably attachedto the outer layer and is also discontinuous in the sense that itcomprises discrete sections each corresponding to one of the localisedareas requiring patching. Resin is applied to the or each discrete linerportion upon eversion of the tube structure, so that the discrete linerportion is bonded to the internal surface of the pipeline at therelevant localised area. Once the resin had cured sufficiently, themembrane defined by the second layer is withdrawn, leaving the linerportions in position as patches within the pipeline. Alternatively, themembrane may be sacrificial.

With this arrangement, resin delivery is appropriately controlled sothat it is applied where necessary to the liner portions to provide thepatches, without unnecessary application in other areas where notrequired.

The tube structure is constructed with the discrete portions of resinabsorbent material constituting the first layer positioned atappropriate locations on the membrane which constitutes the second layerof the tube structure. The locations for positioning of the discreteportions of resin absorbent material would be determined through areconnaissance operation or other analysis of the pipeline asappropriate.

There may also be occasions where it is necessary to apply a patch as astrip extending along the longitudinal extent of the pipeline, or atleast along part of the length thereof, without needing to line theentire pipeline. This can be achieved in a similar fashion to thepatching operation described above, the only difference being that astrip of resin absorbent material constituting the first layer ispositioned at an appropriate location on the membrane constituting thesecond layer of the tube structure. The strip is then applied to thepipeline in a similar fashion to the discrete patches as describedabove.

From the foregoing, it is evident that the present embodiments provide asimple yet highly effective arrangement for ensuring that the evertingtube is properly “wet-out” bonded to the pipe during installation of theliner 11.

Improvements and modification may be incorporated without departing fromthe scope of the invention.

Throughout the specification, unless the context requires otherwise, theword “comprise” or variations such as “comprises” or “comprising”, willbe understood to imply the inclusion of a stated integer or group ofintegers but not the exclusion of any other integer or group ofintegers.

1. Apparatus for lining an internal surface of a conduit, comprising abody adapted to be progressively moved along the conduit for installinga flexible tube structure onto the internal surface, the flexible tubestructure undergoing eversion within the conduit, the body presenting acontact surface against which the tube acts during eversion thereof. 2.Apparatus according to claim 1 wherein the contact surface has means fordelivery of an agent to the everting portion of the tube structure. 3.Apparatus according to claim 2 wherein the means for delivery of theagent comprises a plurality of ports in the contact surface, the portscommunicating with a supply of the agent.
 4. Apparatus according toclaim 3 wherein the contact surface is defined by a plate havingapertures therein incorporating the ports and the plate is eitherrigidly supported or elastically supported.
 5. (canceled)
 6. (canceled)7. Apparatus according to claim 2 wherein the agent comprises a curableresin and the tube structure comprises a resin absorbent material. 8.Apparatus according to claim 7 wherein the plate has a face defining thecontact surface and an opposed face thereof providing a boundary for aresin chamber from which resin may be delivered to the contact face byway of the apertures therein.
 9. Apparatus according to claim 8 whereinthe body has provision for applying resin to the surface onto which theliner is presented.
 10. Apparatus according to claim 9 wherein the bodycomprises a circumferential chamber which is exposed to the surface andwhich contains resin which is wiped on the surface.
 11. Apparatusaccording to claim 10 wherein the circumferential chamber is definedbetween two spaced apart seals for sliding and sealing contact with thesurface, and an inner wall extending between the two seals. 12.Apparatus according to claim 11 wherein the inner wall is defined by aflexible membrane.
 13. Apparatus according to claim 12 wherein the bodyfurther comprises one or more additional chambers one adjacent anotheraxially spaced along the body.
 14. Apparatus according to claim 1wherein the body incorporates a leading section for performingpreparatory work on the interior surface of the conduit.
 15. Apparatusaccording to claim 1 wherein the forward portion of the apparatusincorporates a collection means for collecting debris within the conduitprior to installation of the liner.
 16. Apparatus according to claim 1wherein the tube structure is delivered to the body in a collapsedcondition and opened during eversion thereof.
 17. (canceled) 18.Apparatus according to claim 16 wherein the collapsed condition involvesat least one re-entrant fold.
 19. Apparatus according to claim 17wherein an installation cable is provided in the collapsed tubestructure for assisting axial movement thereof while in the collapsedcondition.
 20. Apparatus according to claim 16 further comprising meansfor establishing a “wet-out” region within the collapsed tube structureprior to eversion thereof.
 21. Apparatus according to claim 20 whereinsaid means comprises a lance structure projecting outwardly of thecontact surface and terminating at a free end, with the collapsed tubestructure embracing the lance structure so that the lance structure isinserted in the tube structure as it approaches the contact face foreversion thereagainst.
 22. Apparatus according to claim 21 wherein thefree end of the lance structure is configured to spread the collapsedwall of the tube structure to create a cavity to receive the resin. 23.Apparatus according to claim 1 wherein the body is caused to move alongthe conduit under the application of a driving force.
 24. Apparatusaccording to claim 23 wherein the driving force comprises pressureapplied to the body through the everting tube structure.
 25. Apparatusaccording to claim 24 wherein the driving force further comprises atowing force applied to the body.
 26. Apparatus according to claim 23further comprising means for applying a retarding force to the body tohold up a column of fluid within the resin pressure chamber. 27.Apparatus according to claim 26 wherein the retarding force is appliedby way of a brake sled operatively connected to the body and in frictionengagement with the interior surface of the conduit.
 28. Apparatus forlining a conduit comprising a body adapted to be progressively movedalong the conduit for installing a flexible liner onto the interiorsurface of the conduit or any substrate applied thereto, the flexibleliner comprising a tube structure undergoing eversion within theconduit, the tube comprising resin absorbent material, the bodypresenting a contact surface against which the tube structure actsduring eversion thereof, the contact surface having means for deliveryof a curable resin to the everting portion of the tube structure. 29.(canceled)
 30. A method of lining a conduit comprising: providing a tubeas a liner for the conduit; everting the tube into the conduit wherebythe tube has an inner tube portion, an outer tube portion and aneverting portion extending between the inner and outer tube portions;and causing the exposed face of the everting portion of the tube toslidably engage a contact surface at which a curable resin is presentedto the everting face of impregnation thereof.
 31. A method according toclaim 30 further comprising sensing and/or monitoring selectedconditions associated with installation of the liner and varying theinstallation process as necessary in response to such conditions. 32.(canceled)
 33. (canceled)
 34. (canceled)
 35. (canceled)
 36. (canceled)